Yeah. The one I have is the Ultra, now discontinued. It's analog is the Fitbit One. They are both the initial style that Fitbit launched with.
I didn't realize the Flex was waterproof, which could be a killer feature as I've killed my Ultra once by sweating on it. Apparently the One doesn't have that failure mode:
http://www.fitbit.com/comparison/trackers
Now I'm tempted to upgrade.